ACPAtmospheric Chemistry and PhysicsACPAtmos. Chem. Phys.1680-7324Copernicus PublicationsGöttingen, Germany10.5194/acp-16-293-2016Hygroscopicity of nanoparticles produced from homogeneous nucleation in the
CLOUD experimentsKimJ.AhlmL.Yli-JuutiT.LawlerM.KeskinenH.TröstlJ.https://orcid.org/0000-0002-2807-0348SchobesbergerS.https://orcid.org/0000-0002-5777-4897DuplissyJ.AmorimA.BianchiF.https://orcid.org/0000-0003-2996-3604DonahueN. M.https://orcid.org/0000-0003-3054-2364FlaganR. C.https://orcid.org/0000-0001-5690-770XHakalaJ.HeinritziM.JokinenT.https://orcid.org/0000-0002-1280-1396KürtenA.LaaksonenA.https://orcid.org/0000-0002-1657-2383LehtipaloK.https://orcid.org/0000-0002-1660-2706MiettinenP.PetäjäT.https://orcid.org/0000-0002-1881-9044RissanenM. P.https://orcid.org/0000-0003-0463-8098RondoL.SenguptaK.SimonM.https://orcid.org/0000-0002-4900-7460ToméA.WilliamsonC.WimmerD.https://orcid.org/0000-0002-5539-9958WinklerP. M.EhrhartS.https://orcid.org/0000-0002-6517-5341YeP.KirkbyJ.https://orcid.org/0000-0003-2341-9069CurtiusJ.https://orcid.org/0000-0003-3153-4630BaltenspergerU.KulmalaM.https://orcid.org/0000-0003-3464-7825LehtinenK. E. J.SmithJ. N.https://orcid.org/0000-0003-4677-8224RiipinenI.VirtanenA.annele.virtanen@uef.fiDepartment of Applied Physics, University of Eastern Finland, Kuopio, FinlandDepartment of Applied Environmental Science, Stockholm University, Stockholm, SwedenNational Centre for Atmospheric Research, Boulder, CO 80305, USALaboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen, SwitzerlandDepartment of Physics, P.O. Box 64, 00014 University of Helsinki, Helsinki, FinlandHelsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Helsinki, FinlandCENTRA-SIM, University of Lisbon, Lisbon, PortugalInstitute for Atmospheric and Climate Science, ETH Zurich, 8092 Zurich, SwitzerlandCarnegie Mellon University, Center for Atmospheric Particle Studies, 5000 Forbes Avenue, Pittsburgh, PA 15213, USACalifornia Institute of Technology, 210-41, Pasadena, CA 91125, USADivision of Atmospheric Sciences, P.O. Box 64, 00014 University of Helsinki, Helsinki, FinlandGoethe University of Frankfurt, Institute for Atmospheric and Environmental Sciences, Altenhöferallee 1, 60438 Frankfurt am Main, GermanyUniversity of Innsbruck, Institute for Ion and Applied Physics, 6020 Innsbruck, AustriaFinnish Meteorological Institute, PL 501, 00101 Helsinki, FinlandUniversity of Leeds, School of Earth and Environment, Leeds LS2 9JT, UKUniversity of Beira Interior, Beira, PortugalFaculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, AustriaCERN, 1211 Geneva, SwitzerlandFinnish Meteorological Institute, Kuopio Unit, Kuopio, Finlandnow at: Arctic research center, Korea Polar Research Institute, Incheon, South Koreanow at: Department of Physics, P.O. Box 64, 00014 University of Helsinki, Helsinki, Finlandnow at: Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USAA. Virtanen (annele.virtanen@uef.fi)18January20161612933048June201520July201511November201517December2015This work is licensed under a Creative Commons Attribution 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/This article is available from https://acp.copernicus.org/articles/16/293/2016/acp-16-293-2016.htmlThe full text article is available as a PDF file from https://acp.copernicus.org/articles/16/293/2016/acp-16-293-2016.pdf
Sulfuric acid, amines and oxidized organics have been found to be important
compounds in the nucleation and initial growth of atmospheric particles.
Because of the challenges involved in determining the chemical composition
of objects with very small mass, however, the properties of the freshly
nucleated particles and the detailed pathways of their formation processes
are still not clear. In this study, we focus on a challenging size range,
i.e., particles that have grown to diameters of 10 and 15 nm following
nucleation, and measure their water uptake. Water uptake is useful
information for indirectly obtaining chemical composition of aerosol particles.
We use a nanometer-hygroscopicity tandem differential mobility analyzer
(nano-HTDMA) at subsaturated conditions (ca. 90 % relative humidity at
293 K) to measure the hygroscopicity of particles during the seventh Cosmics
Leaving OUtdoor Droplets (CLOUD7) campaign performed at CERN in 2012. In
CLOUD7, the hygroscopicity of nucleated nanoparticles was measured in the
presence of sulfuric acid, sulfuric acid–dimethylamine, and sulfuric
acid–organics derived from α-pinene oxidation. The hygroscopicity
parameter κ decreased with increasing particle size, indicating
decreasing acidity of particles. No clear effect of the sulfuric acid
concentration on the hygroscopicity of 10 nm particles produced from
sulfuric acid and dimethylamine was observed, whereas the hygroscopicity of
15 nm particles sharply decreased with decreasing sulfuric acid
concentrations. In particular, when the concentration of sulfuric acid was
5.1×106 molecules cm-3 in the gas phase, and the
dimethylamine mixing ratio was 11.8 ppt, the measured κ of 15 nm
particles was 0.31 ± 0.01: close to the value reported for
dimethylaminium sulfate (DMAS) (κDMAS∼0.28).
Furthermore, the difference in κ between sulfuric acid and sulfuric
acid–dimethylamine experiments increased with increasing particle size. The
κ values of particles in the presence of sulfuric acid and organics
were much smaller than those of particles in the presence of sulfuric acid
and dimethylamine. This suggests that the organics produced from α-pinene ozonolysis play a significant role in particle growth even at 10 nm sizes.
Introduction
Aerosol particles can be directly emitted into the atmosphere from natural
and anthropogenic sources (primary aerosols) or can be produced by
gas-to-particle conversion processes (secondary aerosols). They affect the
regional and global climate by absorbing and scattering light and by acting
as cloud condensation nuclei (CCN) and ice nuclei (IN). Although physical
and chemical properties of atmospheric aerosol particles have been widely
studied, large uncertainties remain, both in their direct and indirect
climate effects (IPCC, 2013). Hygroscopicity, the ability of particles to
take up water, is important when considering aerosol climate effects.
Hygroscopicity of a particle is defined by the particle's composition;
therefore, hygroscopicity can be used for indirectly estimating chemical
composition of size-resolved nanoparticles (Riipinen et al., 2009; Ristovski
et al., 2010; Sakurai et al., 2005).
Experimental and theoretical studies have shown that sulfuric acid is an
important ingredient in particle formation (Kulmala et al., 2004; Weber et
al., 1997). It has also been shown that new particle formation in the
boundary layer cannot be explained by pure sulfuric acid–water nucleation
(Kirkby et al., 2011). Other compounds such as ammonia and/or organics are
needed to explain observed atmospheric particle formation and growth, and
have thus been widely studied. Much of the recent focus has been on the
effect of amines on particle formation. Both experimental and computational
studies have indicated that amines enhance particle formation significantly
more than ammonia (Almeida et al., 2013; Barsanti et al., 2009; Berndt et
al., 2010; Bzdek et al., 2010; Erupe et al., 2011; Kurtén et al., 2008;
Kürten et al., 2014; Loukonen et al., 2010; Paasonen et al., 2012; Pratt
et al., 2009; Zhao et al., 2011). Moreover, alkylaminium salts in
atmospheric particles with sizes of 8–10 nm have been observed during
new-nanoparticle-formation events (Smith et al., 2010). Still, physicochemical
properties of nanoparticles produced by homogeneous nucleation of amines
with sulfuric acid–water and their subsequent growth are not yet well
understood.
Both laboratory experiments and field observations have shown that organic
compounds play important roles in atmospheric particle formation and growth
and make up a large fraction of the submicron aerosol mass (Hallquist et
al., 2009; Jimenez et al., 2009; Metzger et al., 2010; Riccobono et al.,
2014). Most chamber studies have focused either on secondary organic aerosol
(SOA) mass yields or on identifying and quantifying the compounds produced
from oxidation (Griffin et al., 1999; Hao et al., 2011; Hennigan et al.,
2011; Kroll et al., 2005). Chemical aging processes with various oxidants
have also been studied (Donahue et al., 2012; Henry and Donahue, 2012; Henry
et al., 2012; Pierce et al., 2011; Yasmeen et al., 2012). Several useful
studies also have been performed on the hygroscopic properties of SOA
produced either in the laboratory or in the atmosphere, including the effect
of the oxygen-to-carbon (O : C) ratio on hygroscopicity (Chang et al., 2010;
Duplissy et al., 2011; Engelhart et al., 2008; Frosch et al., 2011; Jimenez
et al., 2009; Lambe et al., 2011; Massoli et al., 2010; Roberts et al.,
2010; Sjogren et al., 2008; Varutbangkul et al., 2006; Virkkula et al.,
1999). Jimenez et al. (2009) and Duplissy et al. (2011) found that the
hygroscopicity of SOA increased with increasing oxidation level at
subsaturated conditions (ca. 90–95 % relative humidity (RH)), while Frosch et al. (2011)
showed that the relationship between the hygroscopicity of particles with
diameters in the 59–200 nm range and an O : C ratio in the 0.3–0.6 range was
weak at supersaturated conditions. Massoli et al. (2010) reported that the
hygroscopicity parameter increased with oxidation level both in subsaturated
and supersaturated conditions. Although many studies on physical and
chemical properties of SOA have been performed, there are still significant
gaps in our understanding of the detailed initial growth pathways, and of
the properties of freshly nucleated nanoparticles.
In this study, we focus on determining the hygroscopicity of nanoparticles
generated by homogeneous nucleation of sulfuric acid with organic compounds
such as dimethylamine and α-pinene oxidation products in the Cosmics
Leaving OUtdoor Droplets (CLOUD) chamber at CERN. The measurements were performed with a
nanometer-hygroscopicity tandem differential mobility analyzer (nano-HTDMA)
(Keskinen et al., 2011) during the CLOUD7 experiments. Volume fractions of
inorganic sulfates and dimethylamine sulfate (DMAS) in the nanoparticles
were estimated from nano-HTDMA results and the Zdanovskii–Stokes–Robinson
(ZSR) relation (Choi and Chan, 2002; Kim et al., 2011; Meyer et al., 2009;
Petters and Kreidenweis, 2007). Moreover, simulation results from the
thermodynamic phase equilibrium model E-AIM (Extended Aerosol Inorganics
Model; Clegg et al., 1992; Ge et al., 2011; Wexler and Clegg, 2002;
http://www.aim.env.uea.ac.uk/aim/aim.php) were combined to provide further
information on chemical properties of nucleated nanoparticles.
Experimental methodsCLOUD chamber
The experiments were carried out with the CLOUD chamber at CERN, which has
been described by Kirkby et al. (2011), Almeida et al. (2013) and Duplissy
et al. (2015). In brief, the CLOUD chamber is a cylindrical electropolished
stainless-steel tank with a volume of 26.1 m3.An ultraviolet
(UV) light system which can control the aperture of the UV light (Kupc et
al., 2011) and two stainless-steel fans for mixing vapors (Voigtländer
et al., 2012) are installed in the chamber. During CLOUD7 experiments,
temperature and relative humidity in the chamber were constant at 278 K
(±0.5 K) and 38 % (±1 %), respectively. The experiments
were classified into three groups depending on the nucleation conditions:
neutral (N), ground-level galactic cosmic rays (GCRs), and charged pion beam
(π). In the neutral nucleation experiments, small ions in the chamber
were removed with electric fields (±20 kV). The chamber was exposed
to a positively charged pion beam (Duplissy et al., 2010) during the
charged-pion-beam nucleation experiments, whereas no electric clearing fields and no
pion beam were used under GCR conditions. Precursor vapors such as sulfur
dioxide (SO2), dimethylamine ((CH3)2NH), and α-pinene
(C10H16) were continuously provided into the CLOUD chamber to
produce particles.
Size distributions of particles produced in the chamber were continuously
monitored with a scanning mobility particle sizer (SMPS). The sulfuric acid
concentration was measured using a chemical ionization mass spectrometer
(CIMS) (Kürten et al., 2011); concentrations of dimethylamine, ammonia,
and α-pinene were observed with a proton transfer
reaction time-of-flight mass spectrometer (PTR-TOF-MS) (Schnitzhofer et al.,
2014). The concentrations of SO2 and O3 were also continuously
measured by an SO2 detector (42i-TLE, Thermo Fisher Scientific, Inc.)
and an O3 monitor (TEI 49C, Thermo Environmental Instruments),
respectively. The detailed experimental conditions performed in this study
can be seen in Table 1.
Summary of the experimental conditions. The experiments were
performed in the presence of sulfuric acid (Exp. A), sulfuric acid and
dimethylamine (Exps. B–D), and sulfuric acid and organics produced from
α-pinene ozonolysis (Exps. E–F). H2SO4, (CH3)2NH,
C10H16, and O3 refer to gas concentrations of sulfuric acid,
dimethylamine, α-pinene, and ozone, respectively. Here the error in
the HGF values indicates the standard deviation for the measured results. UV
aperture indicates UV lamp aperture opening (in %), which in turn provides
different UV intensities inside the chamber (Kupc et al., 2011).
The nano-HTDMA system (Keskinen et al., 2011) was applied to determine the
hygroscopic growth of nucleated nanoparticles at a constant subsaturated
relative humidity. It consisted of two different mobility analyzers (DMA1
and DMA2; TSI 3085, USA) (Chen et al., 1998), an aerosol humidifier, and a
condensation particle counter (CPC; TSI 3785, USA), as shown in Fig. 1. The
TDMA measurement technique has been described in previous studies (McMurry
and Stolzenburg, 1989; Hämeri et al., 2000; Sakurai et al., 2005).
Briefly, nanoparticles generated in the CLOUD chamber were dried to about
10–15 % RH and then passed through a bipolar diffusion charger
(85Kr, TSI) before entering the nano-HTDMA system. The nanoparticles
with a certain electrical mobility were classified from charged polydisperse
aerosols by DMA1. The RH of aerosol sample after passing through DMA1 was
∼ 4.5 %. The selected nanoparticles passed through the
aerosol humidifier made out of GoreTex tubing with a 5 s residence time
at the targeted RH. This residence time should be enough for the particles to
reach their equilibrium GF (Duplissy et al., 2009). The RH of the
aerosol flow, the sheath air, and the excess air in DMA2 were
continuously monitored using capacitive RH sensors (Vaisala model HMP 110).
The RH was kept constant to within 1.5 % of the set values. After
humidifying, the size and number concentration of the particles were
measured with DMA2 and the CPC to determine the change in particle size due
to interaction with water vapor. Based on these results, lognormal number
size distributions were fitted to the distributions to estimate the
geometric mean diameter (GMD) with a standard DMA data inversion algorithm
(Reischl, 1991). The use of GMD is relevant for this study as the sampled
aerosol was internally mixed. In this study, the measurements were performed
at 90 ± 1.5 % RH for 10 and 15 nm particles. The flow rate of the
aerosol sample was 1 L min-1. The ratio of sample aerosol flow to sheath air
flow of the DMA was 1 : 10. The size and RH calibration of the nano-HTDMA was
carried out by using ammonium sulfate nanoparticles before, during, and after
the CLOUD7 experiments. The RH calibration was done by measuring the
efflorescence and deliquescence RH of ammonium sulfate particles and by
comparing the values to the theoretical values.
A schematic drawing of the nano-TDMA system used in this study.
Data analysis and theoryHygroscopic growth factor and hygroscopicity parameter κ
The hygroscopic growth factor (HGF) is a measure of the diameter growth of
the size-selected particles at a certain RH compared with dry conditions
and is defined as
HGF=dp,GMD(RH)dp,GMD(dry),
where dp,GMD (RH) is the GMD of the particles at
the elevated RH (ca. 90 %) and dp,GMD (dry) is the GMD for particles at dry
conditions (∼ 4.5 % RH).
In many cases it is useful to represent hygroscopic properties with a single
hygroscopicity parameter κ, defined by Petters and Kreidenweis (2007)
as
κ=HGF3-1KeS-1,
where S is the saturation ratio (S=RH100) and Ke the
Kelvin factor, defined as
Ke=exp4MwσwRTρwdp.
Here Mw is the molecular weight of water, σw the surface
tension of the water, R the ideal gas constant, T the temperature, ρw the density of water, and dp the diameter after humidification
(dp,GMD (RH) =dp,GMD (dry) × HGF). The κ values are in the range
of 0 for insoluble particles such as black carbon to larger than 1 for
water-soluble salt particles (Jurányi et al., 2009; Petters and
Kreidenweis, 2007).
In order to obtain indirect chemical composition information from the
nano-HTDMA results in experiments B–D (Table 1), we use the
ZSR relation, which assumes that the water
uptake volume of a mixture is the independent sum of the water uptake volume
of each individual component. The organic volume fraction can then be
estimated by assuming a two-component system consisting of organic and
inorganic sulfate as (Keskinen et al., 2013)
εDMAS=κ-κinorgκDMAS-κinorg,
where κ is the hygroscopicity obtained from the nano-HTDMA
measurements and κDMAS and κinorg are the
hygroscopicity parameters for DMAS and inorganic
sulfates, respectively. Although ammonia was not injected into the chamber
during these experiments, measurements by the Thermal Desorption Chemical
Ionization Mass Spectrometer (TDCIMS; Smith et al., 2004) showed that
ammonium is a significant constituent of 5–20 nm particles during these
new-particle-formation events (Lawler et al., 2016). Therefore, we calculated the
DMAS volume fraction by assuming that the inorganic sulfates in the particles
are either sulfuric acid or ammonium sulfate. Keskinen et al. (2013) showed
that the hygroscopic properties of particles at a diameter of 150 nm in the
presence of sulfuric acid and ammonia are in good agreement with theoretical
predictions of ammonium sulfate. The κinorg values of
sulfuric acid and ammonium sulfate were assumed as 0.70 (Sullivan et al.,
2010) and 0.47 (Topping et al., 2005), respectively. The κDMAS was assumed as 0.28 derived from hygroscopic growth factors
for dry diameters 80–240 nm measured by Qiu and Zhang (2012).
Thermodynamic equilibrium modeling
The E-AIM was used to estimate the molecular ratio of bases and acids for
particles consisting of sulfuric acid, dimethylamine, and ammonia. In the
model, acid deprotonation and base protonation are taken into account in the
aqueous phase. Sulfuric acid is a strong acid and is assumed to deprotonate
at least singly when present in aqueous solutions. It may also deprotonate a
second time to form sulfate ions. Dimethylamine and ammonia are bases that
have a single protonation product. Mole fractions of the deprotonated acids
and protonated bases are estimated using the acid dissociation constants of
the compounds defined in E-AIM (Ge et al., 2011). The density of the aqueous
solution in the model is parameterized according to Clegg et al. (2013), and
the surface tension is obtained from measurements by Hyvärinen et al. (2004). The E-AIM does not take into account the surface curvature of
particles. Thus, when estimating the water uptake of a nanoparticle with a
certain dry size and composition, the equilibrium vapor pressure for water
vapor obtained from E-AIM needs to be corrected for the Kelvin effect by
multiplication with the Kelvin term, which requires iterating to find the
equilibrium.
Based on the TDCIMS observation (Lawler et al., 2016), we assumed that
particles consisted of sulfuric acid, dimethylamine, and ammonia and that the
base in the particle consisted of 50 % dimethylamine and 50 %
ammonia. Also, we assumed that no particle evaporation took place in the
sampling lines or in the instrument. The assumption was tested by modelling
the particle evaporation in the sampling lines and inside the HTDMA, and based
on the model results the evaporation was negligible (Ahlm et al., 2016). By
calculating the water uptake (and the resulting HGF) in E-AIM for particles
of different base / acid molecular ratios, the composition of the particles
could be estimated.
Comparison of the hygroscopicity (κ) for 10 and 15 nm
particles in the presence of sulfuric acid (Exp. A), sulfuric
acid–dimethylamine (Exp. D), and sulfuric acid–organics produced by α-pinene oxidation with OH scavenger (Exps. E–F). The theoretical κ
of sulfuric acid (solid line) from Sullivan et al. (2010), κ of
ammonium sulfate (dashed line) from Topping et al. (2005), and κ of
DMAS (dashed dotted line) from Qiu and Zhang (2012) are also presented. The
α-pinene concentrations during sulfuric acid–organic I and sulfuric
acid–organic II were 420 and 910 ppt, respectively, as can be seen in Table 1. Error bars show a standard deviation from measurements data.
Results and discussionThe role of dimethylamine- or α-pinene-related secondary organic
compounds in the hygroscopicities of nucleated nanoparticles
In this section, the role of dimethylamine or secondary organic compounds
from the oxidation of α-pinene in defining the hygroscopicities of
nanoparticles is investigated (Exps. A and D–F). The concentrations of
sulfuric acid, dimethylamine, and α-pinene in the chamber for the
different experiments are shown in Table 1. The κ values of 10 and
15 nm particles produced by sulfuric acid, sulfuric acid–dimethylamine, and
sulfuric acid–organics are shown in Fig. 2. In Exp. A, the hygroscopicities
of particles in the presence of sulfuric acid only were examined. The κ values (± standard deviation) of nucleated nanoparticles were
0.64 ± 0.02 and 0.52 ± 0.02 for 10 and 15 nm, respectively (the
HGF of 10 and 15 nm particles were 1.55 ± 0.02 and 1.56 ± 0.02,
as shown in Table 1). Here the error bars represent the standard deviation of
the measurements from the mean value. The κ values are slightly lower
than previous results for sulfuric acid (κH2SO4∼ 0.7) reported elsewhere (Shantz et al., 2008; Sullivan et al., 2010).
Also, the theoretical value for κH2SO4 for 10 nm
particle at 90 %, corresponding to our experimental conditions (residual
water taken into account) and calculated by E-AIM, is 0.7 (at 90 % RH). In
should be noted that the sulfuric acid solution droplet is highly unideal.
Hence, the calculated κ value from E-AIM depends strongly on both
humidity and particle size. The reason for the lower measured κ
values of the nucleated nanoparticles can be twofold: (1) existence of trace
levels of contaminants such as ammonia and dimethylamine in the chamber
and/or (2) residual water in the nanoparticle after passing through DMA1.
Although we supplied only sulfuric acid to the chamber and an overnight
cleaning cycle (100 ∘C for 12 h) was performed to remove
contaminants before experiments, the atmospheric pressure interface
time-of-flight mass spectrometer (APi-TOF) measurements showed that trace
levels of ammonia and dimethylamine still remained in the clusters
(< 2 nm) (Bianchi et al., 2014), most probably due to wall
adsorption from previous experiments. Ammonia and dimethylamine were also
found in the nanoparticles (< 40 nm) from TDCIMS measurements
(Lawler et al., 2016). This observation suggests that trace levels of these
ammonia and dimethylamine in the chamber may be present in the nucleated
nanoparticles, hence decreasing the κ values.
The hygroscopic properties of nucleated nanoparticles in the presence of
sulfuric acid and dimethylamine were determined in Exp. D. Although
dimethylamine was continuously supplied into the chamber to maintain a
concentration of 23.8 ppt, the observed κ values for 10 nm
particles agree to within 4 % with the results for particles in the
presence of sulfuric acid, as can be seen in Fig. 2. In the case of the
15 nm particles, however, the hygroscopicities of sulfuric
acid–dimethylamine particles were 12 % lower than those for sulfuric acid
particles. This decline of hygroscopicity for 15 nm particles is probably
caused by an increasing amount of aminium salts during the growth process.
The E-AIM model results show that the observed decreases in κ values
could be explained by decreasing particle acidity with increasing particle
size, as shown in Table 2. Our results indicate that the ratio of
dimethylamine to sulfuric acid increases when particles grow from 10 to
15 nm. It should be noted that the monodisperse particle growth model
MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) predicts lower acidity in the 10 and 15 nm particles than do the
HTDMA-based estimates under the same experimental conditions (Ahlm et al.,
2016). The reason for this discrepancy is still unknown; it may be related to
measurement uncertainties in the 10–15 nm size range, or to the
incomplete understanding of the growth process of particles formed from
sulfuric acid and dimethylamine. Chan and Chan (2013) observed evaporation of
dimethylamine from aminium sulfate particles upon drying at 3 % RH using
an electrodynamic balance. Ouyang et al. (2015) also concluded that dry
particles consisting of dimethylamine and sulfuric acid in the size range of
5–8.5 nm would be unstable under ambient conditions. In our HTDMA
measurements the particles were dried before measuring the growth factor;
therefore some of the dimethylamine may have evaporated from the particles
prior to growth factor measurements, increasing the acidity of the particles.
Based on the thermodynamic condensation model simulation, the base / acid molar
ratio may have decreased in the sampling line as much as 15 % (in the
experiment with 40 ppt of dimethylamine) (Ahlm et al., 2016) compared to the
value in the chamber. However, the difference between the base / acid ratio of
growing particles predicted with the model and that derived from measured
growth factors is much larger than this. It is, therefore, unlikely that
evaporation of dimethylamine alone would explain this discrepancy.
We also investigated the hygroscopicities of nanoparticles produced in the
chamber in the presence of α-pinene, sulfuric acid, and O3
(Exps. E and F). In these experiments, hydrogen (H2) was added to
suppress OH radicals from α-pinene ozonolysis in order to probe the
role of ozonolysis alone on new particle formation (Praplan et al., 2015).
Although the concentrations of sulfuric acid were higher during the sulfuric
acid–organics experiments than during the sulfuric acid–dimethylamine
experiments, the HGFs of particles in the presence of sulfuric acid and
organics were much smaller than those of particles in the presence of
sulfuric acid and dimethylamine, as can be seen in Table 1. As shown in Fig. 2, the hygroscopicity of 10 nm particles when α-pinene ozonolysis
products are present is significantly lower than observed in the sulfuric
acid or sulfuric acid–dimethylamine experiments; moreover it decreases with
increasing size. It has previously been reported that the hygroscopicity of
organics from α-pinene oxidation is clearly lower than the
hygroscopicity of sulfuric acid (or ammonia-containing sulfate compounds)
(Qiu and Zhang, 2012; Massoli et al., 2010). Hence, the present results
indicate that the organic-oxidation products contribute significantly to the
composition of both 10 and 15 nm particles and, thereby, to their growth.
Molecular ratio of base to acid compounds from the E-AIM model,
assuming no evaporation of dimethylamine from the particles. The E-AIM
results were derived from the HGF results of particles. Based on TDCIMS
measurements, we assumed that the acid compound is only sulfuric acid and
that base compounds consist of 50 % ammonia and 50 % dimethylamine in the
particles.
No.ExperimentsMolecular ratio (base / acid) 10 nm15 nmASulfuric acid–0.7DSulfuric acid–dimethylamine0.31.0The effect of the sulfuric acid concentration on the hygroscopicity of
particles in the presence of sulfuric acid and dimethylamine
We also investigated the effect of sulfuric acid concentration on the
hygroscopicity of 10 and 15 nm particles (Exps. B–D); while SO2 and
dimethylamine were continuously added to the chamber at a constant rate, the
UV light intensity was varied by changing the light aperture. The sulfuric
acid monomer concentrations at an aperture of 20, 40, and 100 % UV were
5.1 ×106, 7.6 ×106, and 12.3×106 molecules cm-3, respectively; in the discussion that follows
we will refer to these concentrations as low, medium, and high, respectively.
The growth rate (GR) of particles from 4 to 15 nm diameter increases from
2.35 to 8.41 nm h-1 with increasing sulfuric acid concentration from
5.1×106 to 12.3×106 molecules cm-3. The large
increase in the GR is probably due to a combination of the enhanced kinetic
condensation of sulfuric acid (and dimethylamine) molecules and the increase
in the number concentration of the formed particles, enhancing growth by
coagulation (Ahlm et al., 2016). However, there were no remarkable
differences among the hygroscopicities of 10 nm particles, as shown in
Fig. 3a. The κ values (± standard deviation) of the 10 nm
particles were 0.58 ± 0.01, 0.60 ± 0.01, and 0.61 ± 0.02
for low, medium, and high sulfuric acid concentrations, respectively. This
suggests that the composition of 10 nm particles does not change
significantly over this range of sulfuric acid and dimethylamine gas-phase
concentrations.
(a) Comparison of hygroscopicity of 10 and 15 nm particles produced
from sulfuric acid and dimethylamine. (b–c) Estimated volume fractions in
the particles depending on UV aperture (Exps. B–D) assuming the inorganic
fraction was (b) sulfuric acid and had a hygroscopicity κ=0.70
and (c) ammonium sulfate and had a hygroscopicity κ=0.47. The
concentrations of sulfuric acid were 5.1×106, 7.6×106, and 12.3×106 molecules cm-3 for low, medium,
and high, respectively.
In contrast to the insensitivity of hygroscopicity for 10 nm particles to
sulfuric acid levels, the hygroscopicity of 15 nm particles increases with
increasing gas-phase sulfuric acid (i.e., with increasing UV intensity). The
κ values (± standard deviation) were 0.31 ± 0.01,
0.42 ± 0.02, and 0.45 ± 0.02 for low, medium, and high sulfuric
acid concentrations, respectively. Especially, the κ value for the
low gas-phase sulfuric acid concentration was close to that of DMAS at
90 % RH (κDMAS∼ 0.28) (Qiu and Zhang, 2012). This
suggests that more aminium salts were involved in 15 nm particles with
decreasing gas-phase sulfuric acid concentrations. The DMAS volume fractions
(± standard deviation) derived from Eq. (4) using experimentally
derived sulfuric acid hygroscopicity for the inorganic sulfate (κinorg= 0.70) varied from 0.29 ± 0.03 to 0.20 ± 0.05
for 10 nm particles and from 0.92 ± 0.02 to 0.58 ± 0.03 for 15 nm
particles depending on the gas-phase sulfuric acid concentrations (Fig. 3b).
Due to the observation of ammonia in the particles the DMAS volume fraction
in 10 nm particles was also calculated assuming that the inorganic fraction
was ammonium sulfate (κinorg= 0.47) to investigate how much
the uncertainty in inorganic composition can affect the calculations. This
assumption resulted in lower DMAS volume fractions for 15 nm particles
compared to the assumption of inorganic sulfate being sulfuric acid (Fig. 3c). The measured κ of 10 nm particles were too high to be explained
with a combination of ammonium sulfate and DMAS. In summary, with each value
of κinorg there is a clear increase in the DMAS volume fraction
from 10 to 15 nm. Hence our measurements support the view that the
contribution of dimethylamine to particle growth increases with increasing
particle size.
Summary and conclusions
The hygroscopic properties of nucleated nanoparticles in the presence of
sulfuric acid, sulfuric acid–dimethylamine, and sulfuric acid combined with
organics derived from α-pinene ozonolysis were investigated with the nano-HTDMA.
The hygroscopicities decreased with increasing particle size, consistent
with a decrease of particle acidity with increased particle size. The
obtained hygroscopicity parameter (κ) values of 10 nm particles in
the presence of sulfuric acid–dimethylamine were similar to those of
particles in the presence of sulfuric acid with trace levels of contaminants
within 4 % (the κ values of sulfuric acid–dimethylamine and
sulfuric acid were 0.61 ± 0.02 and 0.64 ± 0.02, respectively). For
15 nm particles, however, the hygroscopicities of sulfuric
acid–dimethylamine particles were lower by 12 % compared to the results
for the sulfuric acid particles. This finding suggests that the contribution
of dimethylamine to growth increases as the particles grow from 10 to 15 nm.
In the presence of sulfuric acid and organics, the HGFs were much smaller
than in the presence of sulfuric acid and dimethylamine regardless of the
sulfuric acid concentration. This is because the hygroscopicities of
organics derived from α-pinene oxidation were smaller than those of
dimethlyaminium sulfate (generally the hygroscopicity of
α-pinene-derived organic material is close to a value of 0.1; see e.g. Pajunoja et al.,
2015) and/or α-pinene oxidation products contributed more to the
particles mass. In contrast to the sulfuric acid–dimethylamine experiments,
the hygroscopicities of 10 nm particles in sulfuric acid–organic experiments
were clearly lower than in the sulfuric acid experiments; moreover, the
hygroscopicity decreased with increasing size, indicating that the organic
compounds are able to contribute significantly to growth and composition of
both 10 and 15 nm particles. This is probably due to the very low saturation
vapor pressures of organic compounds produced from α-pinene
oxidation (Ehn et al., 2014).
Acknowledgements
We would like to thank CERN for supporting CLOUD with important technical
and financial resources, and for providing a particle beam from the CERN
Proton Synchrotron. We also thank P. Carrie, L.-P. De Menezes, J. Dumollard,
F. Josa, I. Krasin, R. Kristic, A. Laassiri, O. S. Maksumov, B. Marichy, H. Martinati, S. V. Mizin, R. Sitals, A. Wasem, and M. Wilhelmsson for their
important contributions to the experiment. We thank the CSC Centre for
Scientific Computing in Espoo, Finland, for computer time. This research has
received funding from the EC Seventh Framework Programme (Marie Curie
Initial Training Network CLOUD-ITN no. 215072, MC-ITN CLOUD-TRAIN no. 316662, ERC Starting Grant MOCAPAF no. 57360, ERC Consolidator Grant
NANODYNAMITE no. 616075, ERC Advanced Grant ATMNUCLE no. 227463, and ERC
Starting Grant “QAPPA” grant no. 335478); the German Federal Ministry of
Education and Research (project nos. 01LK0902A and 01LK1222A); the Swiss
National Science Foundation (project nos. 200020 135307, 200021 140663,
206021 144947/1, 20FI20 149002/1, and 200021 140663); the Academy of Finland Centre of Excellence program (project
no. 1118615); the Academy of Finland (135054,
133872, 251427, 1389515, 139656, 139995, 137749, 141217, 141451, 2720541,
259005, 264989); the Finnish Funding Agency for Technology and Innovation;
the Nessling Foundation; the Strategic Funding from University of Eastern
Finland; the Austrian Science Fund (FWF; project no. P19546 and L59321); the
Portuguese Foundation for Science and Technology (project no. CERN/FP/116387/ 2010); the Swedish Research Council, Vetenskapsrådet
(grant 2011-5120); the Presidium of the Russian Academy of Sciences and
Russian Foundation for Basic Research (grants 08-02-91006-CERN and
12-02-91522-CERN); the U.S. National Science Foundation (grants AGS1136479
and CHE1012293); a Davidow Grant to Caltech's Global Environmental Science
Program; Dreyfus Award EP-11-117; the French National Research Agency (ANR);
the Nord-Pas de Calais; the European Funds for Regional Economic Development
(FEDER, Labex-Cappa, ANR-11-LABX-0005-01); and the French Civil Aviation
Office (MERMOSE).
Edited by: H. Su
References
Ahlm, L., Yli-Juuti, T., Schobesberger, S., Praplan, A. P., Kim, J.,
Tikkanen, O. -P, Lawler, M. J., Smith, J. N., Tröstl, J., Acosta Navarro,
J. C., Baltensperger, U., Bianchi, F., Donahue, N. M., Duplissy, J.,
Franchin, A., Jokinen, T., Keskinen, H., Kürten, A., Laaksonen, A.,
Lehtipalo, K., Petäjä, T., Riccobono, F., Rissanen, M. P., Rondo, L.,
Schallhart, S., Simon, M., Winkler, P. M., Worsnop, D. R., Virtanen, A., and
Riipinen, I.: Modeling the thermodynamics and kinetics of sulfuric
acid-dimethylamine-water nanoparticle growth in the CLOUD chamber, Aerosol
Sci. Technol., in review, 2016.
Almeida, J., Schobesberger, S., Kürten, A., Ortega, I. K., Kupiainen,
O., Praplan, A., Adamov, A., Amorim, A., Bianchi, F., Breitenlechner, M.,
David, A., Dommen, J., Donahue, N. M., Downard, A., Dunne, E., Duplissy, J.,
Ehrhart, S., Flagan, R. C., Franchin, A., Guida, R., Hakala, J., Hansel, A.,
Heinritzi, M., Henschel, H., Jokinen, T., Junninen, H., Kajos, M.,
Kangasluoma, J., Keskinen, H., Kupc, A., Kurtén, T., Kvashin, A.,
Laaksonen, A., Lehtipalo, K., Leiminger, M., Leppä, J., Loukonen, V.,
Makhmutov, V., Mathot, S., McGrath, M. J., Nieminen, T., Olenius, T.,
Onnela, A., Petäjä, T., Riccobono, F., Riipinen, I., Rissanen, M.,
Rondo, L., Ruuskanen, T., Santos, F. D., Sarnela, N., Schallhart, S.,
Schnitzhofer, R., Seinfeld, J. H., Simon, M., Sipilä, M., Stozhkov, Y.,
Stratmann, F., Tomé, A., Tröstl, J., Tsagkogeorgas, G., Vaattovaara,
P., Viisanen, Y., Virtanen, A., Vrtala, A., Wagner, P. E., Weingartner, E.,
Wex, H., Williamson, C., Wimmer, D., Ye, P., Yli-Juuti, T., Carslaw, K.,
Kulmala, M., Curtius, J., Baltensperger, U., Worsnop, D. R., Vehkamäki,
H., and Kirkby, J.: Molecular understanding of sulfuric acid-amine particle
nucleation in the atmosphere, Nature, 502, 359–363, 2013.Barsanti, K. C., McMurry, P. H., and Smith, J. N.: The potential contribution
of organic salts to new particle growth, Atmos. Chem. Phys., 9, 2949–2957,
10.5194/acp-9-2949-2009, 2009.Berndt, T., Stratmann, F., Sipilä, M., Vanhanen, J., Petäjä, T.,
Mikkilä, J., Grüner, A., Spindler, G., Lee Mauldin III, R., Curtius,
J., Kulmala, M., and Heintzenberg, J.: Laboratory study on new particle
formation from the reaction OH + SO2: influence of experimental
conditions, H2O vapour, NH3 and the amine tert-butylamine on the
overall process, Atmos. Chem. Phys., 10, 7101–7116,
10.5194/acp-10-7101-2010, 2010.
Bianchi, F., Praplan, A. P., Sarnela, N., Dommen, J., Kürten, A., Ortega,
I. K., Schobesberger, S., Junninen, H., Simon, M., Tröstl, J., Jokinen,
T., Sipilä, M., Adamov, A., Amorim, A., Almeida, J., Breitenlechner, M.,
Duplissy, J., Ehrhart, S., Flagan, R. C., Franchin, A., Hakala, J., Hansel,
A., Heinritzi, M., Kangasluoma, J., Keskinen, H., Kim, J., Kirkby, J.,
Laaksonen, A., Lawler, M. J., Lehtipalo, K., Leiminger, M., Makhmutov, V.,
Mathot, S., Onnela, A., Petäjä, T., Riccobono, F., Rissanen, M. P.,
Rondo, L., Tomé, A., Virtanen, A., Viisanen, Y., Williamson, C., Wimmer,
D., Winkler, P. M., Ye, P., Curtius, J., Kulmala, M., Worsnop, D. R.,
Donahue, N. M., and Baltensperger, U.: Insight into acid-base nucleation
experiments by comparison of the chemical composition of positive, negative,
and neutral clusters, Environ. Sci. Technol., 48, 13675–13684, 2014.Bzdek, B. R., Ridge, D. P., and Johnston, M. V.: Amine exchange into ammonium
bisulfate and ammonium nitrate nuclei, Atmos. Chem. Phys., 10, 3495–3503,
10.5194/acp-10-3495-2010, 2010.
Chan, L. P. and Chan, C. K.: Role of the aerosol phase state in
ammonia/amines exchange reactions, Environ. Sci. Technol., 47, 5755–5762,
2013.Chang, R. Y.-W., Slowik, J. G., Shantz, N. C., Vlasenko, A., Liggio, J.,
Sjostedt, S. J., Leaitch, W. R., and Abbatt, J. P. D.: The hygroscopicity
parameter (κ) of ambient organic aerosol at a field site subject to
biogenic and anthropogenic influences: relationship to degree of aerosol
oxidation, Atmos. Chem. Phys., 10, 5047–5064, 10.5194/acp-10-5047-2010,
2010.
Chen, D. R., Pui, D. Y. H., Hummes, D., Fissan, H., Quant, F. R., and Sem, G.
J.: Design and evaluation of a nanometer aerosol differential mobility
analyzer (Nano-DMA), J. Aerosol Sci., 29, 497–509, 1998.
Choi, M. Y. and Chan, C. K.: The effects of organic species on the
hygroscopic behaviors of inorganic aerosols, Environ. Sci. Technol., 36,
2422–2428, 2002.
Clegg, S. L., Pitzer, K. S., and Brimblecombe, P.: Thermodynamics of
multicomponent, miscible, ionic solutions. 2. Mixtures including
unsymmetrical electrolytes, J. Phys. Chem., 96, 9470–9479, 1992.
Clegg, S. L., Qiu, C., and Zhang, R.: The deliquescence behaviour,
solubilities, and densities of aqueous solutions of five methyl- and
ethyl-aminium sulphate salts, Atmos. Environ., 73, 145–158, 2013.
Donahue, N. M., Henry, K. M., Mentel, T. F., Kiendler-Scharr, A., Spindler,
C., Bohn, B., Brauers, T., Dorn, H. P., Fuchs, H., Tillmann, R., Wahner, A.,
Saathoff, H., Naumann, K. H., Möhler, O., Leisner, T., Müller, L.,
Reinnig, M. C., Hoffmann, T., Salo, K., Hallquist, M., Frosch, M., Bilde, M.,
Tritscher, T., Barmet, P., Praplan, A. P., DeCarlo, P. F., Dommen, J.,
Prévôt, A. S. H., and Baltensperger, U.: Aging of biogenic secondary
organic aerosol via gas-phase OH radical reactions, P. Natl. Acad. Sci. USA,
109, 13503–13508, 2012.Duplissy, J., Gysel, M., Sjogren, S., Meyer, N., Good, N., Kammermann, L.,
Michaud, V., Weigel, R., Martins dos Santos, S., Gruening, C., Villani, P.,
Laj, P., Sellegri, K., Metzger, A., McFiggans, G. B., Wehrle, G., Richter,
R., Dommen, J., Ristovski, Z., Baltensperger, U., and Weingartner, E.:
Intercomparison study of six HTDMAs: results and recommendations, Atmos.
Meas. Tech., 2, 363–378, 10.5194/amt-2-363-2009, 2009.Duplissy, J., Enghoff, M. B., Aplin, K. L., Arnold, F., Aufmhoff, H.,
Avngaard, M., Baltensperger, U., Bondo, T., Bingham, R., Carslaw, K.,
Curtius, J., David, A., Fastrup, B., Gagné, S., Hahn, F., Harrison, R.
G., Kellett, B., Kirkby, J., Kulmala, M., Laakso, L., Laaksonen, A.,
Lillestol, E., Lockwood, M., Mäkelä, J., Makhmutov, V., Marsh, N. D.,
Nieminen, T., Onnela, A., Pedersen, E., Pedersen, J. O. P., Polny, J.,
Reichl, U., Seinfeld, J. H., Sipilä, M., Stozhkov, Y., Stratmann, F.,
Svensmark, H., Svensmark, J., Veenhof, R., Verheggen, B., Viisanen, Y.,
Wagner, P. E., Wehrle, G., Weingartner, E., Wex, H., Wilhelmsson, M., and
Winkler, P. M.: Results from the CERN pilot CLOUD experiment, Atmos. Chem.
Phys., 10, 1635–1647, 10.5194/acp-10-1635-2010, 2010.Duplissy, J., DeCarlo, P. F., Dommen, J., Alfarra, M. R., Metzger, A.,
Barmpadimos, I., Prevot, A. S. H., Weingartner, E., Tritscher, T., Gysel, M.,
Aiken, A. C., Jimenez, J. L., Canagaratna, M. R., Worsnop, D. R., Collins, D.
R., Tomlinson, J., and Baltensperger, U.: Relating hygroscopicity and
composition of organic aerosol particulate matter, Atmos. Chem. Phys., 11,
1155–1165, 10.5194/acp-11-1155-2011, 2011.Duplissy, J., Merikanto, J., Franchin, A., Tsagkogeorgas, G., Kangasluoma,
J., Wimmer, D., Vuollekoski, H., Schobesberger, S., Lehtipalo, K., Flagan,
R.C., Brus, D., Donahue, N.M., Vehkämäki, H., Almeida, J., Amorim,
A., Barmet, P., Bianchi, F., Breitenlechner, M., Dunne, E. M., Guida, R.,
Henschel, H., Junninen, H., Kirkby, J., Kürten, A., Kupc, A.,
Määttänen, A., Makhmutov, V., Mathot, S., Nieminen, T., Onnela,
A., Praplan, A. P., Riccobono, F., Rondo, L., Steiner, G., Tome, A., Walther,
H., Baltensperger, U., Carslaw, K. S., Dommen, J., Hansel, A.,
Petäjä, T., Sipilä, M., Stratmann, F., Vrtala, A., Wagner, P. E.,
Worsnop, D. R., Curtius, J., and Kulmala, M.: Effect of ions on sulfuric
acid-water binary particle formation II: Experimental data and comparison
with QC-normalized classical nucleation theory, J. Geophys. Res.-Atmos., 120,
in press, 10.1002/2015JD023539, 2016.
Ehn, M., Thornton, J. A., Kleist, E., Sipilä, M., Junninen, H., Pullinen,
I., Springer, M., Rubach, F., Tillmann, R., Lee, B., Lopez-Hilfiker, F.,
Andres, S., Acir, I. H., Rissanen, M., Jokinen, T., Schobesberger, S.,
Kangasluoma, J., Kontkanen, J., Nieminen, T., Kurtén, T., Nielsen, L. B.,
Jørgensen, S., Kjaergaard, H. G., Canagaratna, M., Maso, M. D., Berndt,
T., Petäjä, T., Wahner, A., Kerminen, V. M., Kulmala, M., Worsnop, D.
R., Wildt, J., and Mentel, T. F.: A large source of low-volatility secondary
organic aerosol, Nature, 506, 476–479, 2014.Engelhart, G. J., Asa-Awuku, A., Nenes, A., and Pandis, S. N.: CCN activity
and droplet growth kinetics of fresh and aged monoterpene secondary organic
aerosol, Atmos. Chem. Phys., 8, 3937–3949, 10.5194/acp-8-3937-2008,
2008.Erupe, M. E., Viggiano, A. A., and Lee, S.-H.: The effect of trimethylamine
on atmospheric nucleation involving H2SO4, Atmos. Chem. Phys., 11,
4767–4775, 10.5194/acp-11-4767-2011, 2011.Frosch, M., Bilde, M., DeCarlo, P. F., Jurányi, Z., Tritscher, T.,
Dommen, J., Donahue, N. M., Gysel, M., Weingartner, E., and Baltensperger,
U.: Relating cloud condensation nuclei activity and oxidation level of
α-pinene secondary organic aerosols, J. Geophys. Res.-Atmos., 116,
D22212, 10.1029/2011JD016401, 2011.
Ge, X., Wexler, A. S., and Clegg, S. L.: Atmospheric amines – Part II.
Thermodynamic properties and gas/particle partitioning, Atmos. Environ., 45,
561–577, 2011.
Griffin, R. J., Cocker Iii, D. R., Flagan, R. C., and Seinfeld, J. H.:
Organic aerosol formation from the oxidation of biogenic hydrocarbons, J.
Geophys. Res.-Atmos., 104, 3555–3567, 1999.Hallquist, M., Wenger, J. C., Baltensperger, U., Rudich, Y., Simpson, D.,
Claeys, M., Dommen, J., Donahue, N. M., George, C., Goldstein, A. H.,
Hamilton, J. F., Herrmann, H., Hoffmann, T., Iinuma, Y., Jang, M., Jenkin, M.
E., Jimenez, J. L., Kiendler-Scharr, A., Maenhaut, W., McFiggans, G., Mentel,
Th. F., Monod, A., Prévôt, A. S. H., Seinfeld, J. H., Surratt, J. D.,
Szmigielski, R., and Wildt, J.: The formation, properties and impact of
secondary organic aerosol: current and emerging issues, Atmos. Chem. Phys.,
9, 5155–5236, 10.5194/acp-9-5155-2009, 2009.
Hämeri, K., Väkevä, M., Hansson, H. C., and Laaksonen, A.:
Hygroscopic growth of ultrafine ammonium sulphate aerosol measured using an
ultrafine tandem differential mobility analyzer, J. Geophys. Res.-Atmos.,
105, 22231–22242, 2000.Hao, L. Q., Romakkaniemi, S., Yli-Pirilä, P., Joutsensaari, J.,
Kortelainen, A., Kroll, J. H., Miettinen, P., Vaattovaara, P., Tiitta, P.,
Jaatinen, A., Kajos, M. K., Holopainen, J. K., Heijari, J., Rinne, J.,
Kulmala, M., Worsnop, D. R., Smith, J. N., and Laaksonen, A.: Mass yields of
secondary organic aerosols from the oxidation of α-pinene and real
plant emissions, Atmos. Chem. Phys., 11, 1367–1378,
10.5194/acp-11-1367-2011, 2011.Hennigan, C. J., Miracolo, M. A., Engelhart, G. J., May, A. A., Presto, A.
A., Lee, T., Sullivan, A. P., McMeeking, G. R., Coe, H., Wold, C. E., Hao,
W.-M., Gilman, J. B., Kuster, W. C., de Gouw, J., Schichtel, B. A., Collett
Jr., J. L., Kreidenweis, S. M., and Robinson, A. L.: Chemical and physical
transformations of organic aerosol from the photo-oxidation of open biomass
burning emissions in an environmental chamber, Atmos. Chem. Phys., 11,
7669–7686, 10.5194/acp-11-7669-2011, 2011.Henry, K. M. and Donahue, N. M.: Photochemical aging of α-pinene
secondary organic aerosol: Effects of OH radical sources and photolysis, J.
Phys. Chem. A, 116, 5932–5940, 2012.Henry, K. M., Lohaus, T., and Donahue, N. M.: Organic aerosol yields from
α-pinene oxidation: Bridging the gap between first-generation yields
and aging chemistry, Environ. Sci. Technol., 46, 12347–12354, 2012.Hyvärinen, A. P., Lihavainen, H., Hautio, K., Raatikainen, T., Viisanen,
Y., and Laaksonen A.: Surface Tensions and Densities of Sulfuric
Acid + Dimethylamine + Water Solutions, J. Chem. Eng. Data, 49,
917–922, 2004.
IPCC: Climate change 2013: The physical science basis, Intergovernmental
panel on Climate Change, Cambridge University Press, New York, USA, 571–740,
2013.
Jimenez, J. L., Canagaratna, M. R., Donahue, N. M., Prévôt, A. S. H.,
Zhang, Q., Kroll, J. H., DeCarlo, P. F., Allan, J. D., Coe, H., Ng, N. L.,
Aiken, A. C., Docherty, K. S., Ulbrich, I. M., Grieshop, A. P., Robinson, A.
L., Duplissy, J., Smith, J. D., Wilson, K. R., Lanz, V. A., Hueglin, C., Sun,
Y. L., Tian, J., Laaksonen, A., Raatikainen, T., Rautiainen, J., Vaattovaara,
P., Ehn, M., Kulmala, M., Tomlinson, J. M., Collins, D. R., Cubison, M. J.,
Dunlea, E. J., Huffman, J. A., Onasch, T. B., Alfarra, M. R., Williams, P.
I., Bower, K., Kondo, Y., Schneider, J., Drewnick, F., Borrmann, S., Weimer,
S., Demerjian, K., Salcedo, D., Cottrell, L., Griffin, R., Takami, A.,
Miyoshi, T., Hatakeyama, S., Shimono, A., Sun, J. Y., Zhang, Y. M., Dzepina,
K., Kimmel, J. R., Sueper, D., Jayne, J. T., Herndon, S. C., Trimborn, A. M.,
Williams, L. R., Wood, E. C., Middlebrook, A. M., Kolb, C. E., Baltensperger,
U., and Worsnop, D. R.: Evolution of organic aerosols in the atmosphere,
Science, 326, 1525–1529, 2009.Jurányi, Z., Gysel, M., Duplissy, J., Weingartner, E., Tritscher, T.,
Dommen, J., Henning, S., Ziese, M., Kiselev, A., Stratmann, F., George, I.,
and Baltensperger, U.: Influence of gas-to-particle partitioning on the
hygroscopic and droplet activation behaviour of α-pinene secondary
organic aerosol, Phys. Chem. Chem. Phys., 11, 8091–8097, 2009.
Keskinen, H., Romakkaniemi, S., Jaatinen, A., Miettinen, P., Saukko, E.,
Jorma, J., Makela, J. M., Virtanen, A., Smith, J. N., and Laaksonen, A.:
On-line characterization of morphology and water adsorption on fumed silica
nanoparticles, Aerosol Sci. Technol., 45, 1441–1447, 2011.Keskinen, H., Virtanen, A., Joutsensaari, J., Tsagkogeorgas, G., Duplissy,
J., Schobesberger, S., Gysel, M., Riccobono, F., Slowik, J. G., Bianchi, F.,
Yli-Juuti, T., Lehtipalo, K., Rondo, L., Breitenlechner, M., Kupc, A.,
Almeida, J., Amorim, A., Dunne, E. M., Downard, A. J., Ehrhart, S., Franchin,
A., Kajos, M.K., Kirkby, J., Kürten, A., Nieminen, T., Makhmutov, V.,
Mathot, S., Miettinen, P., Onnela, A., Petäjä, T., Praplan, A.,
Santos, F. D., Schallhart, S., Sipilä, M., Stozhkov, Y., Tomé, A.,
Vaattovaara, P., Wimmer, D., Prevot, A., Dommen, J., Donahue, N. M., Flagan,
R.C., Weingartner, E., Viisanen, Y., Riipinen, I., Hansel, A., Curtius, J.,
Kulmala, M., Worsnop, D. R., Baltensperger, U., Wex, H., Stratmann, F., and
Laaksonen, A.: Evolution of particle composition in CLOUD nucleation
experiments, Atmos. Chem. Phys., 13, 5587–5600,
10.5194/acp-13-5587-2013, 2013.
Kim, J.-S., Kim, Y. J., and Park, K.: Measurements of hygroscopicity and
volatility of atmospheric ultrafine particles in the rural Pearl River Delta
area of China, Atmos. Environ., 45, 4661–4670, 2011.
Kirkby, J., Curtius, J., Almeida, J., Dunne, E., Duplissy, J., Ehrhart, S.,
Franchin, A., Gagné, S., Ickes, L., Kürten, A., Kupc, A., Metzger,
A., Riccobono, F., Rondo, L., Schobesberger, S., Tsagkogeorgas, G., Wimmer,
D., Amorim, A., Bianchi, F., Breitenlechner, M., David, A., Dommen, J.,
Downard, A., Ehn, M., Flagan, R. C., Haider, S., Hansel, A., Hauser, D., Jud,
W., Junninen, H., Kreissl, F., Kvashin, A., Laaksonen, A., Lehtipalo, K.,
Lima, J., Lovejoy, E. R., Makhmutov, V., Mathot, S., Mikkilä, J.,
Minginette, P., Mogo, S., Nieminen, T., Onnela, A., Pereira, P.,
Petäjä, T., Schnitzhofer, R., Seinfeld, J. H., Sipilä, M.,
Stozhkov, Y., Stratmann, F., Tomé, A., Vanhanen, J., Viisanen, Y.,
Vrtala, A., Wagner, P. E., Walther, H., Weingartner, E., Wex, H., Winkler, P.
M., Carslaw, K. S., Worsnop, D. R., Baltensperger, U., and Kulmala, M.: Role
of sulfuric acid, ammonia and galactic cosmic rays in atmospheric aerosol
nucleation, Nature, 476, 429–435, 2011.Kroll, J. H., Ng, N. L., Murphy, S. M., Flagan, R. C., and Seinfeld, J. H.:
Secondary organic aerosol formation from isoprene photooxidation under
high-NOx conditions, Geophys. Res. Lett., 32, 1–4, 2005.
Kulmala, M., Vehkamäki, H., Petäjä, T., Dal Maso, M., Lauri, A.,
Kerminen, V. M., Birmili, W., and McMurry, P. H.: Formation and growth rates
of ultrafine atmospheric particles: A review of observations, J. Aerosol.
Sci., 35, 143–176, 2004.Kupc, A., Amorim, A., Curtius, J., Danielczok, A., Duplissy, J., Ehrhart, S.,
Walther, H., Ickes, L., Kirkby, J., Kürten, A., Lima, J. M., Mathot, S.,
Minginette, P., Onnela, A., Rondo, L., and Wagner, P. E.: A fibre-optic UV
system for H2SO4 production in aerosol chambers causing minimal
thermal effects, J. Aerosol. Sci., 42, 532–543, 2011.Kürten, A., Rondo, L., Ehrhart, S., and Curtius, J.: Performance of a
corona ion source for measurement of sulfuric acid by chemical ionization
mass spectrometry, Atmos. Meas. Tech., 4, 437–443,
10.5194/amt-4-437-2011, 2011.
Kürten, A., Jokinen, T., Simon, M., Sipilä, M., Sarnela, N.,
Junninen, H., Adamov, A., Almeida, J., Amorim, A., Bianchi, F.,
Breitenlechner, M., Dommen, J., Donahue, N. M., Duplissy, J., Ehrhart, S.,
Flagan, R. C., Franchin, A., Hakala, J., Hansel, A., Heinritzi, M., Hutterli,
M., Kangasluoma, J., Kirkby, J., Laaksonen, A., Lehtipalo, K., Leiminger, M.,
Makhmutov, V., Mathot, S., Onnela, A., Petäjä, T., Praplan, A. P.,
Riccobono, F., Rissanen, M. P., Rondo, L., Schobesberger, S., Seinfeld, J.
H., Steiner, G., Tomé, A., Tröstl, J., Winkler, P. M., Williamson,
C., Wimmer, D., Ye, P., Baltensperger, U., Carslaw, K. S., Kulmala, M.,
Worsnop, D. R., and Curtius, J.: Neutral molecular cluster formation of
sulfuric acid-dimethylamine observed in real time under atmospheric
conditions, P. Natl. Acad. Sci. USA, 111, 15019–15024, 2014.Kurtén, T., Loukonen, V., Vehkamäki, H., and Kulmala, M.: Amines are
likely to enhance neutral and ion-induced sulfuric acid-water nucleation in
the atmosphere more effectively than ammonia, Atmos. Chem. Phys., 8,
4095–4103, 10.5194/acp-8-4095-2008, 2008.Lambe, A. T., Onasch, T. B., Massoli, P., Croasdale, D. R., Wright, J. P.,
Ahern, A. T., Williams, L. R., Worsnop, D. R., Brune, W. H., and Davidovits,
P.: Laboratory studies of the chemical composition and cloud condensation
nuclei (CCN) activity of secondary organic aerosol (SOA) and oxidized primary
organic aerosol (OPOA), Atmos. Chem. Phys., 11, 8913–8928,
10.5194/acp-11-8913-2011, 2011.
Lawler, M., Smith, J. N., Winkler, P. M., Tröstl, J., Praplan, A.,
Schobesberger, S., Kim, J., Virtanen, A., Ahlm, L., Riipinen, I., and CLOUD
Consortium: Acidic freshly nucleated sulfate particle: Relative roles of
dimethylamine and ammonia, in preparation, 2016.Loukonen, V., Kurtén, T., Ortega, I. K., Vehkamäki, H., Pádua, A.
A. H., Sellegri, K., and Kulmala, M.: Enhancing effect of dimethylamine in
sulfuric acid nucleation in the presence of water – a computational study,
Atmos. Chem. Phys., 10, 4961–4974, 10.5194/acp-10-4961-2010, 2010.Massoli, P., Lambe, A. T., Ahern, A. T., Williams, L. R., Ehn, M.,
Mikkilä, J., Canagaratna, M. R., Brune, W. H., Onasch, T. B., Jayne, J.
T., Petäjä, T., Kulmala, M., Laaksonen, A., Kolb, C. E., Davidovits,
P., and Worsnop, D. R.: Relationship between aerosol oxidation level and
hygroscopic properties of laboratory generated secondary organic aerosol
(SOA) particles, Geophys. Res. Lett., 37, L24801, 10.1029/2010GL045258,
2010.
McMurry, P. H. and Stolzenburg, M. R.: On the sensitivity of particle size to
relative humidity for Los Angeles aerosols, Atmos. Environ., 23, 497–507,
1989.
Metzger, A., Verheggen, B., Dommen, J., Duplissy, J., Prévôt, A. S.
H., Weingartner, E., Riipinen, I., Kulmala, M., Spracklen, D. V., Carslaw, K.
S., and Baltensperger, U.: Evidence for the role of organics in aerosol
particle formation under atmospheric conditions, P. Natl. Acad. Sci. USA,
107, 6646–6651, 2010.Meyer, N. K., Duplissy, J., Gysel, M., Metzger, A., Dommen, J., Weingartner,
E., Alfarra, M. R., Prevot, A. S. H., Fletcher, C., Good, N., McFiggans, G.,
Jonsson, Å. M., Hallquist, M., Baltensperger, U., and Ristovski, Z. D.:
Analysis of the hygroscopic and volatile properties of ammonium sulphate
seeded and unseeded SOA particles, Atmos. Chem. Phys., 9, 721–732,
10.5194/acp-9-721-2009, 2009.Ouyang, H., He, S., Larriba-Andaluz, C., and Hogan, C. J.: IMS–MS and
IMS–IMS Investigation of the Structure and Stability of
Dimethylamine-Sulfuric Acid Nanoclusters, J. Phys. Chem. A, 119, 2026–2036,
10.1021/jp512645g, 2015.Paasonen, P., Olenius, T., Kupiainen, O., Kurtén, T., Petäjä, T.,
Birmili, W., Hamed, A., Hu, M., Huey, L. G., Plass-Duelmer, C., Smith, J. N.,
Wiedensohler, A., Loukonen, V., McGrath, M. J., Ortega, I. K., Laaksonen, A.,
Vehkamäki, H., Kerminen, V.-M., and Kulmala, M.: On the formation of
sulphuric acid – amine clusters in varying atmospheric conditions and its
influence on atmospheric new particle formation, Atmos. Chem. Phys., 12,
9113–9133, 10.5194/acp-12-9113-2012, 2012.Pajunoja, A., Lambe, A. T., Hakala, J., Rastak, N., Cummings, M. J., Brogan,
J. F., Hao, L., Paramonov, M., Hong, J., Prisle, N. L., Malila, J.,
Romakkaniemi, S., Lehtinen, K. E. J., Laaksonen, A., Kulmala, M., Massoli,
P., Onasch, T. B., Donahue, N. M., Riipinen, I., Davidovits, P., Worsnop, D.
R., Petäjä, T., and Virtanen, A.: Adsorptive uptake of water by
semisolid secondary organic aerosols, Geophys. Res. Lett., 42, 3063–3068,
10.1002/2015gl063142, 2015.Petters, M. D. and Kreidenweis, S. M.: A single parameter representation of
hygroscopic growth and cloud condensation nucleus activity, Atmos. Chem.
Phys., 7, 1961–1971, 10.5194/acp-7-1961-2007, 2007.Pierce, J. R., Riipinen, I., Kulmala, M., Ehn, M., Petäjä, T.,
Junninen, H., Worsnop, D. R., and Donahue, N. M.: Quantification of the
volatility of secondary organic compounds in ultrafine particles during
nucleation events, Atmos. Chem. Phys., 11, 9019–9036,
10.5194/acp-11-9019-2011, 2011.Praplan, A. P., Schobesberger, S., Bianchi, F., Rissanen, M. P., Ehn, M.,
Jokinen, T., Junninen, H., Adamov, A., Amorim, A., Dommen, J., Duplissy, J.,
Hakala, J., Hansel, A., Heinritzi, M., Kangasluoma, J., Kirkby, J., Krapf,
M., Kürten, A., Lehtipalo, K., Riccobono, F., Rondo, L., Sarnela, N.,
Simon, M., Tomé, A., Tröstl, J., Winkler, P. M., Williamson, C., Ye,
P., Curtius, J., Baltensperger, U., Donahue, N. M., Kulmala, M., and Worsnop,
D. R.: Elemental composition and clustering behaviour of α-pinene
oxidation products for different oxidation conditions, Atmos. Chem. Phys.,
15, 4145–4159, 10.5194/acp-15-4145-2015, 2015.
Pratt, K. A., Hatch, L. E., and Prather, K. A.: Seasonal volatility
dependence of ambient particle phase amines, Environ. Sci. Technol., 43,
5276–5281, 2009.
Qiu, C. and Zhang, R.: Physiochemical properties of alkylaminium sulfates:
Hygroscopicity, thermostability, and density, Environ. Sci. Technol., 46,
4474–4480, 2012.
Reischl, G. P.: Measurement of ambient aerosols by the differential mobility
analyzer method: Concepts and realization criteria for the size range between
2 and 500 nm, Aerosol Sci. Technol., 14, 5–24, 1991.
Riccobono, F., Schobesberger, S., Scott, C. E., Dommen, J., Ortega, I. K.,
Rondo, L., Almeida, J., Amorim, A., Bianchi, F., Breitenlechner, M., David,
A., Downard, A., Dunne, E. M., Duplissy, J., Ehrhart, S., Flagan, R. C.,
Franchin, A., Hansel, A., Junninen, H., Kajos, M., Keskinen, H., Kupc, A.,
Kürten, A., Kvashin, A. N., Laaksonen, A., Lehtipalo, K., Makhmutov, V.,
Mathot, S., Nieminen, T., Onnela, A., Petäjä, T., Praplan, A. P.,
Santos, F. D., Schallhart, S., Seinfeld, J. H., Sipilä, M., Spracklen, D.
V., Stozhkov, Y., Stratmann, F., Tomé, A., Tsagkogeorgas, G.,
Vaattovaara, P., Viisanen, Y., Vrtala, A., Wagner, P. E., Weingartner, E.,
Wex, H., Wimmer, D., Carslaw, K. S., Curtius, J., Donahue, N. M., Kirkby, J.,
Kulmala, M., Worsnop, D. R., and Baltensperger, U.: Oxidation products of
biogenic emissions contribute to nucleation of atmospheric particles,
Science, 344, 717–721, 2014.Riipinen, I., Manninen, H. E., Yli-Juuti, T., Boy, M., Sipilä, M., Ehn,
M., Junninen, H., Petäjä, T., and Kulmala, M.: Applying the
Condensation Particle Counter Battery (CPCB) to study the water-affinity of
freshly-formed 2–9 nm particles in boreal forest, Atmos. Chem. Phys., 9,
3317–3330, 10.5194/acp-9-3317-2009, 2009.Ristovski, Z. D., Suni, T., Kulmala, M., Boy, M., Meyer, N. K., Duplissy, J.,
Turnipseed, A., Morawska, L., and Baltensperger, U.: The role of sulphates
and organic vapours in growth of newly formed particles in a eucalypt forest,
Atmos. Chem. Phys., 10, 2919–2926, 10.5194/acp-10-2919-2010, 2010.Roberts, G. C., Day, D. A., Russell, L. M., Dunlea, E. J., Jimenez, J. L.,
Tomlinson, J. M., Collins, D. R., Shinozuka, Y., and Clarke, A. D.:
Characterization of particle cloud droplet activity and composition in the
free troposphere and the boundary layer during INTEX-B, Atmos. Chem. Phys.,
10, 6627–6644, 10.5194/acp-10-6627-2010, 2010.
Sakurai, H., Fink, M. A., McMurry, P. H., Mauldin, L., Moore, K. F., Smith,
J. N., and Eisele, F. L.: Hygroscopicity and volatility of 4–10 nm
particles during summertime atmospheric nucleation events in urban Atlanta,
J. Geophys. Res.-Atmos., 110, 1–10, 2005.Schnitzhofer, R., Metzger, A., Breitenlechner, M., Jud, W., Heinritzi, M., De
Menezes, L.-P., Duplissy, J., Guida, R., Haider, S., Kirkby, J., Mathot, S.,
Minginette, P., Onnela, A., Walther, H., Wasem, A., Hansel, A., and the CLOUD
Team: Characterisation of organic contaminants in the CLOUD chamber at CERN,
Atmos. Meas. Tech., 7, 2159–2168, 10.5194/amt-7-2159-2014, 2014.Shantz, N. C., Leaitch, W. R., Phinney, L., Mozurkewich, M., and
Toom-Sauntry, D.: The effect of organic compounds on the growth rate of cloud
droplets in marine and forest settings, Atmos. Chem. Phys., 8, 5869–5887,
10.5194/acp-8-5869-2008, 2008.Sjogren, S., Gysel, M., Weingartner, E., Alfarra, M. R., Duplissy, J., Cozic,
J., Crosier, J., Coe, H., and Baltensperger, U.: Hygroscopicity of the
submicrometer aerosol at the high-alpine site Jungfraujoch, 3580 m a.s.l.,
Switzerland, Atmos. Chem. Phys., 8, 5715–5729, 10.5194/acp-8-5715-2008,
2008.
Smith, J. N., Moore, K. F., McMurry, P. H., and Eisele, F. L.: Atmospheric
Measurements of Sub-20 nm Diameter Particle Chemical Composition by Thermal
Desorption Chemical Ionization Mass Spectrometry, Aerosol Sci. Technol., 38,
100–110, 2004.
Smith, J. N., Barsantia, K. C., Friedlia, H. R., Ehnd, M., Kulmala, M.,
Collins, D. R., Scheckman, J. H., Williams, B. J., and McMurry, P. H.:
Observations of aminium salts in atmospheric nanoparticles and possible
climatic implications, P. Natl. Acad. Sci. USA, 107, 6634–6639, 2010.Sullivan, R. C., Petters, M. D., DeMott, P. J., Kreidenweis, S. M., Wex, H.,
Niedermeier, D., Hartmann, S., Clauss, T., Stratmann, F., Reitz, P.,
Schneider, J., and Sierau, B.: Irreversible loss of ice nucleation active
sites in mineral dust particles caused by sulphuric acid condensation, Atmos.
Chem. Phys., 10, 11471–11487, 10.5194/acp-10-11471-2010, 2010.Topping, D. O., McFiggans, G. B., and Coe, H.: A curved multi-component
aerosol hygroscopicity model framework: Part 1 – Inorganic compounds, Atmos.
Chem. Phys., 5, 1205–1222, 10.5194/acp-5-1205-2005, 2005.Varutbangkul, V., Brechtel, F. J., Bahreini, R., Ng, N. L., Keywood, M. D.,
Kroll, J. H., Flagan, R. C., Seinfeld, J. H., Lee, A., and Goldstein, A. H.:
Hygroscopicity of secondary organic aerosols formed by oxidation of
cycloalkenes, monoterpenes, sesquiterpenes, and related compounds, Atmos.
Chem. Phys., 6, 2367–2388, 10.5194/acp-6-2367-2006, 2006.
Virkkula, A., Van Dingenen, R., Raes, F., and Hjorth, J.: Hygroscopic
properties of aerosol formed by oxidation of limonene, α-pinene, and
β-pinene, J. Geophys. Res.-Atmos., 104, 3569–3579, 1999.Voigtländer, J., Duplissy, J., Rondo, L., Kürten, A., and Stratmann,
F.: Numerical simulations of mixing conditions and aerosol dynamics in the
CERN CLOUD chamber, Atmos. Chem. Phys., 12, 2205–2214,
10.5194/acp-12-2205-2012, 2012.
Weber, R. J., Marti, J. J., McMurry, P. H., Eisele, F. L., Tanner, D. J., and
Jefferson, A.: Measurements of new particle formation and ultrafine particle
growth rates at a clean continental site, J. Geophys. Res.-Atmos., 102,
4375–4385, 1997.Wexler, A. S. and Clegg, S. L.: Atmospheric aerosol models for systems
including the ions H+, NH4+, Na+, SO42-,
NO3-, Cl-, Br-, and H2O, J. Geophys. Res.-Atmos., 107,
4207, 10.1029/2001JD000451, 2002.Yasmeen, F., Vermeylen, R., Maurin, N., Perraudin, E., Doussin, J. F., and
Claeys, M.: Characterisation of tracers for aging of α-pinene
secondary organic aerosol using liquid chromatography/negative ion
electrospray ionisation mass spectrometry, Environ. Chem., 9, 236–246, 2012.Zhao, J., Smith, J. N., Eisele, F. L., Chen, M., Kuang, C., and McMurry, P.
H.: Observation of neutral sulfuric acid-amine containing clusters in
laboratory and ambient measurements, Atmos. Chem. Phys., 11, 10823–10836,
10.5194/acp-11-10823-2011, 2011.